The Effect Of Danshen Injection On The Expression Of RANKL And OPG During Experimental Orthodontic Tooth Movement

Objective: To investigate the effect of danshen injection on the expression of RANKLand OPG during experimental orthodontic tooth movement (OTM) in ratsMethods: Two hundred and forty male SPF Sprague-Dawley rats wererandomly assigned to four groups. In group A and B,5-mm nickel-titaniumclosed-coil springs were placed between the incisors and maxillary firstmolars to deliver an orthodontic force of40g, and each of the two groupswere administered with0.1ml PBS or danshen injections. Group C was onlyadministered with0.1ml danshen injections, and group D was evaluated ascontrol group with injection of0.1PBS. The injection was performed once aday for every single rat. And the animals were sacrificed by overdoseanesthesia on day1,3,5,7,10and14, and each maxilla was dissected. Thedistances between the first and second molars were measured, and thehistological sections were stained using immunohistochemistry or TRAP. Allstatistical analysis was performed using the SPSS21.0statistical package.The data were expressed as mean±standard deviation. And the data on theextent of orthodontic tooth movement and the number of osteoclasts wereanalyzed by independent sample t-test, and the expression of RANKL andOPG were analyzed by one way ANOVA.Results: From day5till the end of the experiment, group C showed a significant increasein tooth movement (P＜0.05). And there were no significant differences between group Aand B on the expression of RANKL. After day7, the expression of OPG of group C wasmuch higher than group A (P＜0.05). On day3and5, the numbers of osteoclasts of groupC were largely increased when compared to group A. Conclusion: The result suggests that danshen injection may not able to up-regulate theexpression of RANKL, but it could increase the numbers of osteoclasts in the compressionregion during OTM and accelerate tooth movement. And danshen injection couldup-regulate the expression of OPG but cannot move up the time course so that to acceleratetooth movement and maintain the volume of the alveolar bone.